贪心 CodeForces 124B Permutations

题目传送门

 /*
     贪心：全排列函数使用，更新最值
 */
 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 #include <cmath>
 #include <string>
 #include <vector>
 #include <map>
 #include <set>
 #include <iostream>
 #include <queue>
 using namespace std;

 typedef long long ll;
 const int MAXN = ;
 const int INF = 0x3f3f3f3f;
 int b[MAXN];
 char a[MAXN][MAXN];

 int main(void)        //CodeForces 124B Permutations
 {
 //    freopen ("A.in", "r", stdin);

     int n, k;
     while (scanf ("%d%d", &n, &k) == )
     {
         for (int i=; i<=n; ++i)
         {
             scanf ("%s", a[i] + );
         }
         for (int i=; i<=k; ++i)    b[i] = i;

         ll ans = INF;
         do
         {
             ll mx = , mn = INF;    ll sum = ;
             for (int i=; i<=n; ++i)
             {
                 sum = ;
                 for (int j=; j<=k; ++j)
                 {
                     sum = sum *  + (a[i][b[j]] - '');
                 }
                 if (sum > mx)    mx = sum;
                 if (sum < mn)    mn = sum;
             }
             ans = min (ans, mx - mn);
         }while (next_permutation (b+, b++k));

         printf ("%I64d\n", ans);
     }

     return ;
 }